The ever increasing cost of labor has provided great incentive for expanding the use of automation. Accordingly, in recent years, many sewing machine manufacturers have and are continuing to develop sewing machines which automatically move a workpiece beneath the sewing instrumentalities of the machine. In such machines, automatically controlled carriages or carriers, having the workholders secured thereto, respond to digitly controlled means and are effective to move the work beneath the sewing instrumentalities in a programmed mode of operation. Thus, the operator of such a machine is no longer required to guide the workpiece under the sewing instrumentalities. The operator need only position a workpiece in the workholder, secure the workholder to the carriage, remove the workholder at the completion of the sewing operation, and replace the workholder with another. While the machine is operating, the operator is free to remove the sewn workpiece from the released workholder and replace it with another to be sewn so that the workholder is ready for positioning on the carriage for yet another operation.
Even though such automatic machines have reduced the time spent in producing an acceptable workpiece, the operator handling time between operations remains a problem. Between sewing operations, the time spent in replacing one workholder with another must be kept at a minimum for automatic machines to be a profitable investment. Thus, a quick release mechanism which assures accurate positioning of the workholder with respect to the automatically controlled carriage is required. Fastening means, such as bolts or screws will not suffice for it takes too long to effectuate such means. U.S. Pat. No. 3,988,993 issued Nov. 2, 1976 to Robert V. Brophy discloses a workholder that is fitted over pins carried by the automatic carriage. Such an arrangement, however, also suffers drawbacks. It has been found, with a pin type arrangement that the holes in the workholder must align perfectly with the pins on the automatically controlled carriage before the workholder can be dropped over the pins. The operator cannot afford the time required to be assured that perfect alignment between the apertures and pins is provided. Also, the tolerances between the pins and holes needs to be extremely close to prevent chattering of the workholder. Even if such close tolerances could be obtained, at times, a wedging action results whereby requiring the workholder to be forceably removed from the carriage. Thus, the time gained by the automatic operation of the machine, is offset by the time spent in removing the workholder from the automatically controlled carriage. Thus, the need for a quick release mechanism adapted to releasably affix a workholder to a automatically controlled carriage of a sewing machine remains unanswered.